EFFECT OF IONIC LIQUID [C4C1im]Br AS ADDITIVE ON THE FORMATION OF ABS COMPOSED OF PEG400 AND THE SALTS K2CO3 OR (NH4)2SO4 AT T = 298.15 K

Aqueous biphasic systems (ABS) are currently recognized as an efficient pretreatment technique for the extraction and enrichment of bio-molecules in biotechnology. Polyethylene glycols (PEGs) are a class of polymers widely used in typical polymer-salt ABS. However, PEGs present a limited range of applicability, due to the low polarity of the PEG-rich phase. To overcome this limitation, a new approach has recently been proposed based on the use of ionic liquids (ILs) as adjuvants in ABS, enlarging the polarity range of these systems. In this regard, this work is devoted to study the influence of IL 1-butyl-3-methylimidazolium bromide ([C4C1im]Br) as an adjuvant compound on the formation of {PEG 400 + potassium carbonate (K2CO3)} and {PEG 400 + ammonium sulphate ((NH4)2SO4)} ABS. For this purpose, the binodal curves of the studied ABS with the addition of small quantities of IL (at 5 wt%) were determined at T = 298.15 K. The results obtained indicate that the biphasic region of the systems with IL is larger than that of ternary systems.